Rotary-to-reciprocating motion converter



A. J. KOSCH ROTARY-TOREC IPRQCATING MOTION CONVERTER April 19, 1966Filed llll'lillxL INVENTOR. ALols J. KoscH AHovneys United States Patent3,246,528 ROTARY-TO-RECIPROCATING MOTION CONVERTER Alois J. Kosch,Columbus, Nebr.

Filed Apr. 17, 1963, Ser. No. 273,633 7 Claims. (Cl. 7450) The presentinvention relates to a transducer intended to convert rotary motion intoreciprocatory motion, and the primary object of the invention is toprovide a very simple and inexpensive, but highly effective andversatile,

device of the character described.

A further object of the invention is to provide, in such a mechanism,means whereby the power-fluid of a hydraulic motor constituting acomponent of the mechanism, may

be utilized to lubricate. the motion-converting component,

while guarding against the disadvantages which are inherent in operatingsuch a motion converter submerged in oil.

Although the transducer mechanism may be driven by any source of rotarypower, it has been illustrated and will be described in connection witha hydraulic gear motor; and some of the advantages of the transducermechanism find their primary utility in such a hydraulic system. Whilethe reciprocatory output power may be utilized for any desired purpose,the mechanism has been designed primarily for driving the reciprocatingblade of a mower; and the mechanism is illustrated, therefore, in

the form best adapted for high-speed, relatively light duty.

Further objects of the invention will appear as the descriptionproceeds.

v To the accomplishment of the above and related objects, my inventionmay be embodied in the form illustrated in the accompanying drawings,attention being called to the fact, however, that the drawings areillustrative only, and that change may be made in the specificconstruction illustrated and described, so long as the scope of theappended claims is not violated. v

FIG. 1 is an exploded view of the parts of a transducer mechanismconstructed in accordance with the present invention, including a pair'of meshing hydraulic gears output reciprocator.

Referring more particularly to the drawings, the reference numeral 10indicates generally a hydraulic'motor which may be of conventionalconstruction and which includes a housing 11 provided with ports for theaccommodation of an input conduit 12 and an exhaust conduit 13. A pairof shafts 14 and 15 are journalled on parallel axes within the housing11 and meshing hydraulic gears 16 and 17 are drivingly mounted on saidrespective shafts as, for instance, by means of the keys 18 and 19.

The floor of the housing 11 is preferably provided by a separable plate20 which may constitute, also, the roof of a cooperating casing 21, theshafts 14 and 15 penetrating said plate and being journalled therein inany suitable manner which will permit a restricted flow of oil from thehousing 11 into the casing 21.

The lower end of the shaft 14 is reduced and suitably threaded as at 22and the shaft is formed with a conical portion 23 tapering toward itsthreaded end 22. The

portions 23 and 25 and the threaded ends 22 and 24 of the shafts 14 and15 are disposed within the chamber 26 defined by the casing 2 1.

A balance wheel is indicated generally by the reference numeral 27, saidbalance wheel being provided with a central hub 28 having a bore 29 theupper portion of which tapers downwardly in conformity to the shaftportion 23 in order to establish a wedgin-g fit therewith. The parts are.so proportioned that, when the hub 28 is mounted on the shaft 14 thethreaded end 22 of said shaft projects into a pocket in the hub 28 toreceive thereon a nut 30 which may be manipulated to force the hub intotightlywedged engagement on the shaft portion 23.

A lug 31 extends radially from the hub 28 and is formed with a socket 32therethrough upon an axis parallel with, but laterally offset from, theaxis of the bore 29; and the upper end of a crank pin 33 is receivablein the socket 32. A counterweight or flange 34 is symmetricallysup-ported from the hub 28 by a web 35 for a reason which will becomeapparent as the description proceeds.

A similar balance wheel 36 comprises a hub 37 with a similarly taperedbore 38 adapted to be mounted on the lower end of the shaft 15 and to be.wedgingly secured thereto by means of a nut 39. I Said balance wheel 36includes a lug 40 formed with a socket 41 directly analogous to thesocket 32 for the reception of the upper end of a crank pin 42. Thebalance wheel 36 is similarly provided with a counterweight or flange 43supported from the hub 37 by a web 44 analogous to the web 35.

It will be readily perceived that, while the rotational position of thegears 16 and 17 relative tothe shafts 14 and 15 is fixedly establishedby the keys 18 and' 19, the balance wheels 27 and 36 are infinitelyadjustable in their rotational positions relative to the shafts 14 and15, and may be secured in any selected positions of adjustment by meansof the nuts 30 and 39 which act to press the tapered sockets 29 and 38into Wedging engagement with the tapered shaft portions 23 and 25.Normally, the balance wheels will be so mounted on the shafts that twicein each cycle of rotation of the shafts, the axes of the sockets 32 and41 'will be offset in a common direction from the plane which is commonto the axes of the shafts 14 and 15.

The casing 21 is formed to provide a mouth 45 disposed upon an axiswhich is offset below the balance wheels 27 and 36, located midwaybetween the axes of the shafts 14 and 15 and perpendicular to the planewhich is common to said shaft axes. A bushing 46 is fixedly supported insaid casing mouth 45 by any suitable means and guidingly receives areciprocator 47 for reciprocation upon the mouth axis, said bushingbeing suitably constructed to constitute oil seal means between thecasing 21 and the reciproeator 47. A transverse head, indicatedgenerally by the reference numeral 48, is carried at the proximal end ofthe reciprocator 47 within the chamber 26. At least said end portion ofthe reciprocator is hollow and is provided with an axially-open mouth49.

A wall of the casing 241 opposite the casing mouth 45 is formed with aport 50 preferably having an inwardly flaring portion 5-1 coaxial withthe casing mouth 45. A hollow guide pin 54 is formed near its proximalend to fit snugly within the flared portion 51 of the port 50, and athreaded region 55 on said pin extends through, and closes, the port '50to receive a nut 56 whereby said pin may be secured in place in saidport. The distal end of the pin 54 is open as at 57 and is proportionedand designed to be snugly slidably received in the mouth 49 of thereciprocator 47 to assist in the guidance of said reciprocator.

The casing 21 is formed to provide a passage 52 communicating, at itslower end, with the flaring portion 51 "of the port 50 through a reducedport 53, and communicating, at its upper end, with the interior of thehousing 11th-r ough a passage 70 formed in the plate 20. A port 58 nearthe proximal end of the pin 54 is disposed in open communication withthe port 53, while a second port 59 opens laterally from the interior ofthe hollow pin 54 into the chamber 26. A ball check valve 60 rests onthe upper end of the port 53 to close said port against flow of liquiddownwardly through said port toward the interior-of the pin '54; .and,if desired, a spring 71 -may yieldably resist upward, or port-opening,movement of said ball.

The head 48 comprises opposite, laterally extending arms 61 and 62formed with trackway means which, in

the illustrated embodiment of the invention, constitute grooves orchannels '63 and 64 opening upwardly toward the balance wheels 27 and3-6, respectively, and extending rectili-flearly in substantialparallelism with the plane common to the axes of the shafts 14 and 15.As shown, a 'block 65 having an upwardly openingsocket 66 is slidablyreceived in the channel 63 and a similar block 67 having a similarsocket 68 is slidably received in the channel 64, the lower-ends ofthecrank pins 33 and 42 being respectively received in the sockets 66 and68 to provide driving connections between the balance wheels 27 and '36and'the reciprocator 47. The pins 3-3 and 42 and the sockets 32, 65, 41and 68 are so proportioned and designed as to establish snug fits ofsaid pins in their respective sockets, but each pin is rotatable aboutits own axis relative to at Qen-gaged.

least one of the sockets in whichit is The webs 35 and '44 arepreferably perforated, as

shown, to facilitate counterweight loading of the balance wheels, eitherby'casting an appropriate mass of lead therein, as shown at 72, or bymounting precast lead slugs in the perforations. In either case, thebalance wheels are so counterweighted as to balance the entire assemblyincluding the balance wheels, the lugs 31 and 40, the crank pins 33 and42, the blocks 65 and 67 and the reciprocator 47 with its head 48 andits load (for instance, 'a mower knife) to obviate vibration in theassembly. It will be seen that, since the balance Wheels rotate inopposite directions, the loaded flanges and webs will travelsimultaneously away from a median plane between the shaft axes and willtravel simultaneously toward said plane to maintain balance indirections transverse to the line of travel of the reciprocator 47.

From the above description, it will be apparent that,

I when hydraulic fluid under pressure issupplied through 1 the conduit12 to the housing 11, it will cooperate with the teeth of the gears 16and 17 to drive said gears at equal velocities in opposite directions.The gears are, of course, of equal pitch diametersand, since both gearsare hydraulically driven, there is nosignificant transmission of powerbetween them, so that they are not subjected to any significant amountof wear.

The shafts 14 and 15 will be correspondingly rotated The pins 33 and42," being dis- 15, thereby imparting rectilinear reciprocatory motionto "the head 48 and thus to the reciprocator 47. Said reciprooator is,of course, firmly guided within the bushing 46 and upon the pin 54.

As is pointed out above, oil so supplied to the gears 16 and 17 withinthe housing 11 may bleed at a restricted rate past'the' bearings for thelower ends of the shafts 14 and 15 and so into the chamber 26 to bathethe parts within the housing 21. To avoid turbulence and. heating 4which would occur if the chamber 26 were filled with oil, however, Iprovide the scavenging pump consisting of the tube 54 telescoped in theproximal end of the reciprocator 47. As the reciprocator moves towardits illustrated position, it tends to evacuate the interior of the pin54, and any oil in the chamber 26 above the level of the port 59 willflow into said pin, the port 5 3 being closed by the ball 60. Now, asthe reciprocator moves toward the left oil in the pin 54 will be movedtoward the ports 59 and 58, but approximately midway in its stroke themouth 49 of the reciprocator will move past the port 59 to close it,whereafter oil .will be moved through the port 58 to lift the ball andmove into the passage 52. As the reciprocator moves again toward theright, the ball 60 will promptly close the port 53 and the interior ofthe pin 54 will be evacuated so that, when the mouth 49 of thereciprocator-47 clears the port 59, oil will again flow from the chamber2% through that port into the interior of the pin. It will be seen that,through successive cycles, oil will be returned through the passages 52and 70 to the interior of the housing 11, so that the oil level withinthe chamber 26 will never rise significantly above the top of the pin54.

, -Preferably, a breather passage 72' will open from at- 'mosphere intothe chamber 26, a ball check valve 73 .supported by a spring 74 beingprovided therein to in- .hibit fluid flow from said chamber toatmosphere. If desired, filter means 75 may guard the entry to saidpassage 72'. I a v As alternatives to the blocks and 67, the channels 63and 64 may be designed for directengagernent of the lower ends of thepins 33 and 42 therein in light duty applications; orrollers (not shown)may be substituted for said blocks. in slow-speed heavy dutyapplications.

For applications such as the reciprocation of the knife assembly of amower, however, the illustrated blocks are considered to be optimum,since there must-be some play between rollers and channels like thoseillustrated at" 63 and 64, and the rollersmust change the direction oftheir rotation as they engage first with one wall and then with theother wall of such channels.

I claim as my invention: I

1. Transducer mechanism comprising a pair of parallel shafts, a pair-ofmeshing grears fixed to rotate with said respective shafts, a balancewheel for each of said shafts,

- each balance wheel being fixed to rotate with one of said shafts, aclosed casing enclosing said balance wheels, said casing being formedwith a passage opening to the exterior thereof and further being formedwith a mouth dis ,-reciprocator and said casing in the region of saidmouth,

the proximal end of said reciprocator being hollow, a

hollow guide pin stationarily mounted from a Wall of i said casingopposite said mouth and disposed within said casing upon the axis ofreciprocation of said reciprocator, the open distal end of said pinbeing snugly slidably received in the hollow proximal end of saidreciprocator, said pin being formed with a lateral port opening to theinterior of said casing and with a second port opening to said' passage,2. check valvein said passage, and means providing an operativeconnection between said balance wheels and: said reciprocator to convertrotation of said shafts into reciprocation of said reciprocator.

2. -Transducer mechanism comprising a pair of parallel shafts, a pair ofmeshing gears fixed to rotate with said respective shafts, a balancewheel for each of said shafts, each balance wheel being fixed to rotatewith one of said shafts, a closed casing enclosingsaid balance wheels,said casing being formed with a mouth disposed on an axis f midwaybetween the axes of said balance wheels, beyond one end of said shaftsand perpedicular to the plane which is common to said balance wheelaxes, a reciprocator entering said casing through said mouth, meansproviding a seal between said reciprocator and said casing in the regionof said mouth, the proximal end of said reciprocator being hollow, saidcasing being formed, in a wall opposite said mouth, with a port coaxialwith said mouth and said casing futher being formed to provide a passagecommunicating with said wall port and opening to the exterior of saidcasing, a check valve in said passage, a hollow guide pin having itsproximal end mounted in and closing said wall port, said guide pin beingaxially open at its distal end and snugly slidably received in thehollow proximal end of said reciprocator, said pin being formed with afirst lateral port disposed in said wall port and communicatingtherethrough with said passage and said pin further being formed with asecond lateral port communicating with the interior of said casing, andmeans providing an operative connection between said balance wheels andsaid reciprocator to convert rotation of said shafts into reciprocationof said reciprocator.

3. A transducer comprising a gear motor including a housing, a pair ofparallel shafts journalled in said housing and a pair of meshinghydraulic gears drivingly mounted on said shafts, respectively; a casingfixedly secured to said housing, said shafts penetrating into saidcasing, a balance wheel mounted within said casing for rotation witheach shaft, said casing being formed with a passage Opening into saidhousing and further being formed with .a mouth disposed on an axismidway be- :tween the axes of said balance wheels, beyond the adjacentends of said shafts and perpendicular to the plane which is common tothe axes of said balance wheels, a reciprocator entering said casingthrough said mouth, means providing an oil seal between saidreciprocator and said casing in the region of said mouth, the proximalend of said reciprocator being hollow, a hollow guide pin stationarilymounted from a wall of said casing opposite said mouth and disposedwithin said casing upon the axis of reciprocation of said reciprocator,the open distal end of said pin being snugly slidably received in thehollow proximal end of said reciprocator, said pin being formed with alateral port opening to the interior of said casing and with a secondport communicating through said passage with the interior of saidhousing, a check valve in said passage inhibiting fluid flow toward theinterior of said pin, and means providing an operative connectionbetween said balance wheels and said reciprocator to convert rotation ofsaid shafts into reciprocation of said reciprocator.

4. A transducer comprising a gear motor including a housing, a pair ofparallel shafts journalled in said housing and a pair of meshinghydraulic gears drivingly mounted on said shafts, respectively; a casingfixedly secured to said housing, said shafts penetrating into saidcasing, a balance wheel mounted within said casing for rotation witheach shaft, said casing being formed with a mouth disposed on an axismidway between the axes of said balance wheels, beyond the adjacent endsof said shafts and perpendicular to the plane which is common to theaxes of said balance wheels, a reciprocator entering said casing throughsaid mouth, means providing an oil seal between said reciprocator andsaid casing in the region of said mouth, the proximal end of saidreciprocator being hollow, said casing being formed, in a wall oppositesaid mouth, with a port coaxial with said mouth and said casing furtherbeing formed to provide a passage communicating with said wall port andwith the interior of said housing, a check valve in said passageinhibiting fluid flow toward said wall port, a hollow guide pin havingits proximal end mounted in and closing said wall port, said guide pinbeing axially open at its distal end and snugly slidably received in thehollow proximal end of said reciprocator, said pin being formed with afirst lateral port disposed in said wall port and opening to saidpassage and said pin being further formed with a second lateral portcommunicating with the interior of said casing and disposed to bealternately closed and opened on each cycle of said reciprocator, andmeans providing an operative connection between said balance wheels andsaid reciprocator to convert rotation of said shafts into reciprocationof said reciprocator.

5. The transducer of claim 4 in which said casing is provided with abreather port opening from the upper part of said casing to atmosphere.

6. The transducer of claim 5 including valve means inhibiting fluid flowthrough said breather port toward the atmosphere.

7. Transducer mechanism comprising a gear motor including a housinghaving an inlet and an outlet, a pair of parallel shafts, a pair ofmeshing hydraulic gears within said housing between said inlet and saidoutlet and fixed to rotate with said respective shafts, means forestablishing a flow of liquid under pressure from said inlet to saidoutlet through said housing to drive said gears, a balance wheel foreach of said shafts, each balance wheel being fixed to rotate with oneof said shafts, a crank pin for each balance wheel disposed on an axisarranged in offset parallelism with the axis of rotation of theassociated balance wheel, a closed casing enclosing said balance wheels,said casing being formed with a passage opening into said housing andfurther being formed with a mouth disposed on an axis midway between theaxes of said balance wheels, beyond one end of said shafts andperpendicular to the plane which is common to the axes of said balancewheels, a reciprocator entering said casing through said mouth, meansproviding a seal between said reciprocator and said casing in the regionof said mouth, the proximal end of said reciprocator being hollow, ahollow guide pin stationarily mounted from a wall of said casingopposite said mouth and disposed within said casing upon the axis ofreciprocation of said reciprocator, the open distal end of said pinbeing snugly slidably received in the hollow proximal end of saidreciprocator, said pin being formed with a lateral port opening to theinterior of said casing and with a second port opening to said passage,and a check value in said passage, said reciprooator being formed toprovide trackway means elongated in a direction parallel with the planewhich is common to the axes of said shafts, and said crank pinsoperatively engaging said trackway means to convert rotation of saidshafts into reciprocation of said reciprocator.

References Cited by the Examiner J UNITED STATES PATENTS 290,749 12/1883 Cunningham 103-158 981,862 1/1911 Keats 91-87 X 1,372,764 3/1921Miller 103-158 1,494,547 5/1924 Hubbard 74-50 1,551,480 8/1925 Gruman103-158 1,998,751 4/1935 Creveling 103-163 X 2,345,383 3/1944 Curtis74-50 2,639,694 5/1953 Johnson 91-87 2,704,941 3/1955 Holford 74-502,748,608 6/1956 Riley 74-61 2,790,295 4/1957 Collins 74-50 X 2,938,4385/1960 Hamilton 91-87 X 2,988,924 6/ 1961 Cooley 74-50 BROUGHTON G.DURHAM, Primary Examiner.

MILTON KAUFMAN, Examiner.

1. TRANSDUCER MECHANISM COMPRISING A PAIR OF PARALLEL SHAFTS, A PAIR OFMESHING GREARS FIXED TO ROTATE WITH SAID RESPECTIVE SHAFTS, A BALANCEWHEEL FOR EACH OF SAID SHAFTS, EACH BALANCE WHEEL BEING FIXED TO ROTATEWITH ONE OF SAID SHAFTS, A CLOSED CASING ENCLOSING SAID BALANCE WHEELS,SAID CASING BEING FORMED WITH A PASSAGE OPENING TO THE EXTERIOR THEREOFAND FURTHER BEING FORMED WITH A MOUTH DISPOSED ON AN AXIS MIDWAY BETWEENTHE AXES OF SAID BALANCE WHEELS, BEYOND ONE END OF SAID SHAFTS ANDPERPENDICULAR TO THE PLANE WHICH IS COMMON TO THE AXES OF SAID BALANCEWHEELS, A RECIPROCATOR ENTERING SAID CASING THROUGH SAID MOUTH, MEANSPROVIDING A SEAL BETWEEN SAID RECIPROCATOR AND SAID CASING IN THE REGIONOF SAID MOUTH, THE PROXIMAL END OF SAID RECIPROCATOR BEING HOLLOW, AHOLLOW GUIDE PIN STATIONARILY MOUNTED FROM A WALL OF SAID CASINGOPPOSITE SAID MOUTH AND DISPOSED WITHIN SAID CASING UPON THE AXIS OFRECIPROCATION OF SAID RECIPROCATOR, THE OPEN DISTAL END OF SAID PINBEING SNUGLY SLIDABLY RECEIVED IN THE HOLLOW PROXIMAL END OF SAIDRECIPROCATOR, SAID PIN BEING FORMED WITH A LATERAL PORT OPENING TO THEINTERIOR OF SAID CASING AND WITH A SECOND PORT OPENING TO SAID PASSAGE,A CHECK VALVE IN SAID PASSAGE, AND MEANS PROVIDING AN OPERATIVECONNECTION BETWEEN SAID BALANCE WHEELS AND SAID RECIPROCATOR TO CONVERTROTATION OF SAID SHAFTS INTO RECIPROCATION OF SAID RECIPROCATOR.